Method for manufacturing porous structure and method for forming pattern
A pattern forming material contains a block copolymer or graft copolymer and forms a structure having micro polymer phases, in which, with respect to at least two polymer chains among polymer chains constituting the block copolymer or graft copolymer, the ratio between N/(Nc-No) values of monomer units constituting respective polymer chains is 1.4 or more, where N represents total number of atoms in the monomer unit, Nc represents the number of carbon atoms in the monomer unit, No represents the number of oxygen atoms in the monomer unit.
1. A method for forming a pattern comprising:
forming a film made of a pattern forming material comprising a copolymer having a polystyrene derivative and a polymethacrylate derivative containing silsesquioxane on a substrate;
forming a microphase-separated structure in the film;
etching the substrate by using a phase of the poly methacrylate derivative containing silsesquioxane, thereby transferring the pattern of the microphase-separated structure to the substrate.
2. The method according to claim 1 , wherein the polymethacrylate derivative containing silsesquioxane is a polymethacrylate having a unit containing silsesquioxane represented by the following formula, in a side chain:
where R is hydrogen, or unsubstituted or substituted alkyl, aryl or aralkyl.
3. The method according to claim 1 , wherein the polymethacrylate derivative containing silsesquioxane is a block copolymer or a graft copolymer synthesized from a monomer represented by the following formula:
where R is hydrogen, or unsubstituted or substituted alkyl, aryl or aralkyl.
4. The method according to claim 1 , wherein the polystyrene derivative is a styrene-terminated polyethylene oxide macromer (a) represented by the following formula and the poly methacrylate derivative containing silsesquioxane is a graft polymer synthesized from a monomer (b) represented by the following formula:
where R is hydrogen, or unsubstituted or substituted alkyl, aryl or aralkyl.